Apparatus for surfacing sheet material with pigments, varnishes, lacquers, or the like



Aug. 22, 1933. 1,923,909

APPARATUS FOR MENTS,

G. M K. BROWN SURFACTNG SHEET MATERIAL WITH PIG VAR ISH S, LACQUER S, OR THE LIKE 1 Original Filed Feb. 13, 1950 2 Sheets Sheet 1 2 Sheets-Sheet 2 W ll dll G. M K. BROWN Aug-22, 1933.

v APPARATUS FOR SURFACING SHEET MATERIAL WITH PIGMENTS,

VARNISHES, LACQUERS, 0R THE LIKE Original Filed Feb. 13, 1930 Patented Aug. 22, 1933 APPARATUS FOR SURFACING SHEET MA- TERIAL WITH PIGMENTS, VARNISHES, LACQUERS, OR THE LIKE George MacKenzie Brown, London, England Original application February 13, 1930, Serial No.

5 Claims.

This invention comprises improvements in or relating to apparatus for surfacing sheet material With pigments, varnishes, lacquers, waterproofing solutions or the like. The manufacture of marbled papers is a good illustration of the application of this invention, the expression marbled being used in a broad sense to include papers with ornamental coatings, either monochrome or multicolour, not only in forms or patterns which are more or less imitative of marbles, but also in forms, such as waves, washes or stripes, which may be more or less irregular and may sometimes be substantially uniform. In the known hand process of marbling paper, colour is deposited in a tank or tray on the surface of a liquid medium (e. g. a solution of carragheen moss) upon which it will float, and spreading naturally over the whole of that surface the colour forms a thin cohesive film. More or less irregular patterns may be produced in the film by stirring, and thereafter, on application of a sheet of paper to the surface of the liquid, the film adheres to the paper and is removed from the liquid medium on removal of the sheet.

The above process is applicable only to the marbling of single sheets, a sheet at a time, and it will be understood that after the removal of the film a new film must be formed on the surface of the flotation liquid. With certain colours and certain flotation media it is possible from a single film to coat two or .even three or four sheets, but the coatings on the subsequent sheets are thinner than and inferior to that on the first sheet. In any case this hand marbling process is necessarily laborious and costly.

One object of the present invention is to provide an improved and inexpensive apparatus which can be used for the production mechanically and continuously of ornamented sheet material, such as marbled paper, in continuous lengths, or in a succession of single sheets, giving effects such as have prevously been referred to as marbled effect as well as coatings of colour which may be fiat or almost flat.

This invention is based on the fact that films produced by the deposition on a flotation medium of suitable liquid compositions have suflicient tensile strength to enable them to be drawn along the surface of the flotation liquid without disruption. v

The suitable liquid composition may comprise pigments in vehicle or media, such as bo led linseed oil, and/or cellulosic solutions (e. g. a solution of a cellulose ester or ether). The composition may also include thinning agents and/or Divided and this application January 8, 1932. Serial No. 585,431

volatile solvents. Instead of or in addition to pigments, the composition may comprise varnishes, lacquers, waterproofing solutions and dyes.

The apparatus provided by this invention comprises in combination a container for a liquid flotation medium, means for maintainnig a substantially continuous supply of film-forming liquid to the surface of the flotation medium, a guide arranged to dip into-the flotation medium at a station spaced apart from the region at which the film-forming liquid is supplied, and means for traversing a continuous web of sheet material past the guide aforesaid in contact with its immersed edge in such manner as to remove the film by movement thereof in relation to the flotation medium in a direction along its sur face.

It has hitherto been proposed (see for example British specification No. 130,883) to carry out mechanically a marbling process by traversing a continuous web of paper over the surface of a marbling liquid contained in a trough in such manner that successive portions in the length of the web come into contact with the liquid at successive points along the length of the trough. In such a process, which necessitates complicated apparatus (e. g. an annular trough rotatable bodily or a web-carrying cylinder movable bodily round the trough), the pigment is picked up by what is in effect a rolling motion of the receiving surface in relation to that of the marbling liquid. A similar effect is also obtained in another known process in which, e. g. by creating a current" in the flotation liquid, that liquid is moved bodily with the film on it up to a station at which the film is taken off by the paper. The apparatus provided by the present invention depends for its operation upon a different efiect, namely, the movement of a film along the surface of the flotation medium.

In carrying out theinvention there is no rotatable tank or bodily movable cylinder, nor is there any circulation of the flotation liquid through the tank up to the taking-off station. In the apparatus according to the invention a rectangular tank, closed at both ends, is employed. Without movement of this tank and without circulation of the flotation medium through it, the film is drawn off by endwise movement in relation to the flotation medium along its surface.

One example of apparatus which may be employed in the carrying out of this invention will now be described with reference to the accompanying drawings (to some extent diagrammatic) in which- Figure 1 is a side elevation of the machine taken at the line 1--1 in Figure 2.

Figure 2 is a (shortened) plan of the machine shown in Figure 1, and

Figure 3 is an end elevation of the machine.

Like reference numerals indicate like parts throughout the figures.

In the apparatus illustrated the film is formed on the surface of a liquid flotation medium contained in a tray 10. The paper 11 to be coated is mounted on a reel 12 supported above the tray. From this reel the paper is drawn off and passed over a guide roller 13 and then under a doctor 14 which dips into the liquid in the tray 10 to a depth of about a quarter of an inch. In this example the doctor is a fiat blade; it may in other cases be constituted by a roller. After passing under the blade 14 the paper is taken over a guide roller 15 and is then wound on to a reel 16. The blade 14 is located near the back of the tray 10 while near the front thereof the paint or other film-forming material is deposited on the flotation medium from pots or droppers 17 mounted on a bar 18. Each of the droppers 17 (of which any desired number may be provided) has a tapered nozzle the outlet from which is controlled by a needle valve 39 adjustable at will. The droppers 17 are adjustable along the bar 18 to any desired settings. Between the dropper bar 18 and the blade 14 there is located a mechanical agitator comprising a shaft 19 on which is mounted a series of inclined discs 20 so arranged that adjacent discs are at opposite inclinations to the axis of the shaft. The shaft 19 is continuously rotated by a chain drive 21 from a power-driven shaft 22 on which the take-on reel 16 is mounted. The dropper bar 18 is continuously reciprocated, in a direction transverse to the travel of the paper, by means of a crank 23 and connecting rod 24, the crank being on a shaft 25 gear driven from a power shaft 26.

In the operation of this apparatus, the paint or like film-forming liquid is supplied continuously at the front of the tray 10, and at the back of the tray the paper web is continuously traversed through the flotation medium. The liquid delivered from the droppers 17-spreads out naturally over the surface of the flotation medium and forms a thin cohesive film. The reciprocation of the dropper bar 18 ensures the required distribution of the paint over the surface of the flotation medium. Between the region at which the paint is supplied and the region at which the paper is traversed through the tray, the film is agitated by the discs 20 which produce a waveform effect. It will be seen therefore that in the operation of this apparatus there is a continuous formation of film which is drawn off along the surface of the flotation medium on to the paper web.

The movement of the web may exert a certain dragging action on the flotation medium and this may tend to set up return currents which may interfere with the formation and distribution of the film. In order to avoid this difiiculty a still pool may be formed in. the tray 10 by immersing to a slight depth in the flotation medium an open frame 27. As shown in Figure 2 this frame is of about the same width as the blade or doctor 14 and it is of such dimensions that a space is left between the sides of the frame and the adjacent sides of the tray. The paint is dropped into the pool enclosed by the frame, and the space outside the frame allows the flotation medium to recover its level, after the slight displacement caused by the dragging action of the paper, without setting up return currents within the pool.

If desired the agitator shaft 19 in addition to or instead of being rotated, may have imparted to it a reciprocating motion by means ofan eccentric 28 on the shaft 26 and a coupling rod 29. The reciprocation of the. shaft 19 will not usually be required where the agitators take the form of oblique discs such as 20, but with other forms of agitator reciprocation of the shaft may be desirable. It will be appreciated also that in some cases the agitator may be completely omitted from the apparatus, thus allowing the film to follow its natural course. Alternately a fixed comb or like device, through or past which the film will be drawn, may be provided instead of or in addition to the agitator.

In an alternative form (not illustrated) the paint supply means may comprise large containers in which the paint is agitated mechanically (e. g. by a pump), combined with'rubber supply tubes leading from these containers to various points situated above the tray 10. These supply tubes may be arranged to provide either a continuous or an intermittent supply, and they may if desired be furnished with control devices mechanically operated (e. g. by cams) to regulate the delivery of the paint.

The patterns which are produced on the web 11 by the operation of the apparatus depend upon a number of different factors, for example the nature. and movement, if any, of the paint distributing devices, the distance between the paint distributors and the doctor 14, the particular form of agitator employed and the speed of the motion which is imparted to it, and also the speed at which the paper is run through the machine. As will be appreciated different combinations of these factors produce an indefinite number of different patterns. Straight and uniform- 115 ly striped patterns may be produced by dropping the colours into parallel compartments leading up to the doctor 14 or equivalent device, and these compartments may for example be formed by strings, strips or the like stretched across the 120 tray 10 so that they are partly immersed in the flotation medium. i

If desired the movement of the film towards the point at which it is drawn off by the web, may be accelerated mechanically or by hand.

With the apparatus illustrated herein the supply of the paint and the agitation of the film to form patterns is carried out to a large extent mechanically. It is to be understood that either or both of these operations may be effected by 13 hand, and in some cases e. g. in the imitation of fine marbles, it may be preferably to adopt the hand method.

In carrying out the process according to this invention the following film-forming materials 135 have been used successfully (a) printers ink diluted with petrol (b) Reeves waterproof poster colours similarly diluted with petrol and (c) cellulose lacquers diluted with thinners. In general the film-forming materials. should have the 140 following characteristics. They should, when properly diluted, form fairly thick drops which will not sink but will spread out quickly in a film. They must not mix with the flotation medium and finally they should be such that they will 145 readily adhere to the surface of the article to be coated. In the known hand process for the preparation of marbled papers, ox-gall and ,sprinkling water are used (a) to make the special colours used for hand-marbling float better 150 and (b) to make blobs in the film. These materials may also be employed in carrying out the process according to the present invention. Films, of irregular patterns may be produced by depositing the colour on the flotation medium with a spray or by spraying ox-gall, water or other liquids upon the colour.

The flotation medium upon which the film is formed may be an aqueous solution of carragheen moss, or in many cases plain water may be used.

The invention is applicable not only to the coating of paper but also to the treatment of textile material and sheet material generally. In treating textile material the films may comprise a dye or dyes.

While the process in its preferred form is applied to the production of coated sheet material in continuous lengths, the process may also be used for coating a succession of separate sheets by a continuous operation. In the latter case the sheets may be fedone at a time to grippers on a cylinder which rotates in contact with the marbling liquid, or the sheets may be carried by endless bands or the like which are traversed over the surface of the liquid. While it is preferable that the film should be applied direct to the surface of the paper or other sheet material, it is within the invention to employ a film transfer roller or other intermediate film-receiving surface, which takes off the film from the flotation medium and transfers it to the paper or other material to be treated.

The apparatus described herein may be modi -fied in many ways.

For example, two webs of paper may be simultaneously marbled from one tray by having pigment supply means at opposite ends. of the tray and by drawing off two films at the centre of the tray. Similarly, both sides of a web may be marbled by traversing opposite sides of the web through different trays. Again, a web marbled in one tray may be conducted to another where it will receive a coating of a different pigment.

I claim:

1. Apparatus for surfacing sheet material with pigments, varnishes, lacquers, waterproofing solutions or the like, comprising in combination a container for a liquid flotation medium, means for maintaining a substantially continuous supply of film-forming liquid to the surface of the flotation medium, a guide located near the surface of the flotation medium at a station spaced apart from the region at which the film-forming liquid is supplied, means for traversing a continuous web of sheet material under the guide aforesaid in contact with the floating film in such manner as to remove the film by movement thereof in relation to the flotation medium in a direction along its surface and means for preventing bodily movement of the flotation medium towards the guide aforesaid.

2. Apparatus for surfacing sheet material with pigments, varnishes, lacquers, waterproofing solutions and the like, comprising in combination a stationary trough constructed and arranged to contain a liquid flotation medium and to constrain that medium against bodily movement in the trough, reciprocating liquid supply means arranged to maintain a substantially continuous supply of film-forming liquid to the surface of the flotation medium, a guide located near the surface of the flotation medium, at a station spaced apart from the region at which the filmforming liquid is supplied, means for traversing a continuous web of sheet material under the guide aforesaid in contact with the floating film in such manner asto remove the film by movement thereof in relation to the flotation medium in a direction along its surface, and means for preventing bodily movement of the flotation medium towards the guide aforesaid. I

3. Apparatus for surfacing sheet material with pigments, varnishes, lacquers, waterproofing solutions or the like, comprising in combination a stationary container for a liquid flotation medium, means for maintaining a substantially continuous supply of film-forming liquid to the surface of the flotation medium, a guidev located near the surface of the flotation medium at a station spaced apart from the region at which the filmforming liquid is supplied, means for traversing a continuous web of sheet material under the guide aforesaid in contact with the floating film in such manner as to remove the film by movement thereof in relation to the flotation medium in a direction along its surface, and an open framework immersed in the flotation medium and spaced apart inwardly from the sides of the container aforesaid in such manner as to form within the frame a still pool.

4. Apparatus for surfacing sheet material coniprising in combination a stationary tank adapted to contain a liquid flotation medium and constructed and arranged to constrain that medium against bodily movement in the tank, means for maintaining a substantially continuous supply of film-forming liquid to the surface of the flotation medium, means for traversing a film-receiving surface past a fixed station over the tank spaced apart from the'region at which the film-forming liquid is supplied in such manner that successive portions in the length of the film-receiving surface come into contact with the liquid and remove film by movement thereof in relation to the flotation medium in a direction along its surface, and a pattern-forming device stationed between the region at which the film-forming liquid is supplied and the guide past which the paper is traversed and comprising a shaft rotatable about an axis transverse to the direction of movement of the film, and a series of inclined discs mounted on the shaft so as to dip into the flotation medium, adjacent discs of the series being at opposite inclinations to the axis of the shaft.

5. Apparatus for carrying out a flotation coating process in which the coating is effected by stripping a film from a flotation medium by movement of the film relatively to the medium in a direction along the surface of the latter, said apparatus comprising a stationary tank and associated means to contain a flotation liquid and to confine that liquid against bodily movement during the operation of the process, supply means for filmforming liquid located near one end of the tank, a guide arranged to extend into the tank at a station near the opposite end thereof, and means for traversing a continuous web of sheet material past the guide aforesaid in contact with its lower edge.

GEORGE MACKENZIE BROWN. 

